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1.
生物学概念的教学研究   总被引:1,自引:1,他引:0  
对生物学概念的含义、类型、获得方式(概念同化,概念形成)进行了研究,并在此基础上提出了概念教学的基本策略。  相似文献   

2.
洪德元 《生物多样性》2016,24(9):979-662
物种概念(species concept)是生物学家们持续关注的中心问题。物种概念决定物种划分, 而物种划分的合理性关系到生物多样性的研究、保护和可持续利用。本文把现有较流行的物种概念分为6类, 并对它们予以述评后指出: 虽然生物学物种概念、遗传学物种概念、进化物种概念、系统发生物种概念等从不同方面认识了物种的客观真实性和物种的本质, 但在实践中都难以操作。绝大多数物种是由分类学家划分的, 但目前所有的分类学物种概念都包含有不同程度的主观因素, 从而造成物种划分的人为性, 对生物多样性研究造成负面影响。因此, 生物多样性事业需要科学、可操作的物种概念。本文在吸收了生物学物种概念、遗传学物种概念、进化物种概念以及系统发生物种概念等的长处, 也分析了它们的不足和问题的基础上提出一个新的物种概念, 即形态-生物学物种概念。最后, 以芍药属(Paeonia)几个物种的处理为例, 说明这一新的物种概念是可操作的, 划分的物种在形态上区别分明, 易于鉴别。更重要的是, 其结果得到基于25或26个单拷贝或寡拷贝核基因DNA序列所作的系统发生分析的强有力支持。各个物种在系统发生树上形成单系和独立的谱系, 表明其间各自形成独立的基因库, 没有基因交换, 它们独立进化, 有各自的生态位和独立的分布区。因此, 利用这一新的物种概念能够达到预期目标。  相似文献   

3.
通过对8个毒蘑菇菌株的培养特性及生理学习性的研究,描述了其培养特性,确定其生长所需最适温度、最适碳源、最适氮源以及最适pH值。8菌株为:鳞柄白鹅膏(Amanita virosa)、细鳞环柄菇(Lepiota clypelo-laria)、绒白乳菇(Lactarius vellereus)、鹅膏菌(Amanitasp.)、厚环鹅膏(Amanita pachycolea)、珊瑚菌(Ramariaephemeroderma)、白霜杯伞(Clitocybe dealbata)、冠状环柄菇(Lepiota cristata)。  相似文献   

4.
镰刀菌属分类学研究历史与现状   总被引:18,自引:0,他引:18  
张向民 《菌物研究》2005,3(2):59-62
镰刀菌是农作物和经济作物的重要病原菌,其产生的真菌毒素可危及人畜健康。近十几年来欧美的科学家在研究技术上有新的突破,使镰刀菌属种的概念在认识上有迅速的发展,尤其是那些引起谷类作物严重病害,并产生毒素的种类。在我国,从谷类粮食、饲料中检出镰刀菌毒素的现象屡有报道,我们对镰刀菌属种以及产生这些毒素的菌种(菌株)的认识还有待进一步加强。  相似文献   

5.
The What,Why and How of Primate Taxonomy   总被引:5,自引:5,他引:0  
Taxonomy has a well-defined role, which is much more than simply stamp-collecting and pigeon-holing. Species are the units of classification, biogeography and conservation; as such they must be defined as objectively as possible. The biological species concept, still widely used in biology, though predominantly by non-taxonomists and all too often misunderstood, is a process-based concept, which offers no criterion for the classification of allopatric populations beyond inference and hypothesis. The phylogenetic species concept—a pattern-based concept—is as nearly objective as we are likely to get. Amount of difference is not a criterion for recognizing species. It is not possible to insist on monophyly at the specific level, but it is mandatory for the higher categories (genus, family, etc.). The rank we assign to a given supraspecific category should be determined by its time depth.  相似文献   

6.
烟草主要数量性状的遗传效应分析   总被引:7,自引:0,他引:7  
许明辉  王孟宇  龙文虹 《遗传》2000,22(6):395-397
利用红花大金元×青梗,红花大金元×中烟14号P1、P2、F1、F2、B1、B2 6个世代资料对7个农艺性状和4个品质性状进行了基因效应分析。结果表明,性状均不符合简单的加性-显性遗传模型,多数性状加性效应显著而显性效应不显著,在3种互作效应中,所有性状至少有一种显著。互作效应普遍存在,是烟草性状杂种优势表现的主要原因之一。 Abstract:Two tobacco F1 hybrids,F2s,backcrosses B1s and B2s and their parents P1 and P2 were used to estimate the gene effects for 7 agronomic and 4 quality characters.The additive-dominance genetic model was not fit for all characters.The additive effects and the epistatic effects of most characters were significant,but the dominant effect not.The epistatic effects could not be ignored in tobacco breeding.They were one of main causes of heterosis for most characters.  相似文献   

7.
玉米对生基因转育对主要农艺性状影响的研究   总被引:1,自引:1,他引:0  
本研究利用对生基因转育获得的对生与互生近等基因系及其杂交组合,分析了对生基因转育对玉米主要农艺性状的影响。结果表明对生自交系的产量性状一般低于互生自交系;对生系的油脂和淀粉含量高于互生系,而在蛋白质、赖氨酸和色氨酸含量上两者差异不明显;对生基因转育对玉米产量和品质性状间的相关性无不良影响。因此,对生基因的转育不影响玉米的产量和品质性状的同步改良。  相似文献   

8.
Crocodilians show a high degree of cranial variation and convergence throughout their 80 million-year fossil record that complicates their phylogenetic reconstruction. Conflicting phylogenetic results from different data partitions and character homoplasies typify crocodilian phylogeny, and differences between molecular and morphological phylogenetic hypotheses are believed to be associated with the slender-snout skull shape of Gavialis gangeticus and Tomistoma schlegelii. Slender-snout skulls are one of five identified eusuchian cranial ecomorph shape categories (ESCs) thought to reflect functional or ecological specialization. This paper tested the effect of transitions among general, blunt and slender ESCs on cranial character-state distributions in phylogeny using the concentrated changes test. In addition, 'tree-free' character compatibility analysis of character independence was conducted on the morphological character matrix to determine if character correlations are observed independent of specific tree topologies. Results suggest cranial ESCs do affect cranial character-state gains in phylogeny. Concentrated changes identify a broad suite of character-state changes that significantly correlate with transitions to slender, general and blunt ESCs on morphological, molecular and combined-data tree topologies, but numbers of correlated characters for each category differ according to topology. Character compatibility analysis results do not mirror the concentrated changes test results and reflect hierarchically distributed support throughout the data. As cranial ESCs affect character-state transitions, it is possible that nonphylogenetic variables could affect inferences of crocodilian phylogeny by affecting cranial morphology.  相似文献   

9.
王桂芹  王玉良  沈戈 《植物研究》2007,27(2):165-168
利用光学显微技术,对黄瓜(Cucumis sativus)和3种砧木:黑籽南瓜(Cucurbita ficifolia)、南瓜(C. moschata)、丝瓜(Luffa cylindrica) 根的解剖结构进行了比较解剖学研究,探讨了黄瓜及其不同砧木抗病性和抗涝性的植物体结构机制,结果表明:导管的管孔类型、管孔大小、管壁厚度、导管周围木纤维的数量及侵填体的有无等与抗病性相关。木栓厚度,通气组织,管孔直径和导管数量与抗涝性相关。  相似文献   

10.
Using trans-lysozyme gene rice line D2-1-2 and its restorer Zhonghua No.9 as test materials, we studied their agronomic characters and grain qualities under two ecological conditions of Yunnan Province. The results show that there were no significant differences in the agronomic characters between D2-1-2 and Zhonghua No.9, but the seed setting rate and plant height of D2-1-2 were significantly lower, while the protein, amino acid and mineral element (Ca, Fe and Zn in particular) contents in its crude grain were higher than those of Zhonghua No.9. It is suggested that there could be some potential genetic variances in the transgenic plant and the possibly induced environmental risk should be evaluated in multi-plots for several years. __________ Translated from Chinese Journal of Ecology, 2007, 26(2): 209–212 [译自: 生态学杂志]  相似文献   

11.
王兴民  任顺祥  徐彩霞 《昆虫知识》2006,43(6):810-813,F0004
引进天敌越南斧瓢虫Axinoscymnus apioides Kuznetsov & Ren原产于东南亚,是烟粉虱Bemisiatabaci(Gennadius)的重要捕食性天敌之一。文章详细描述越南斧瓢虫的形态特征,并研究其基本的生物学特性。越南斧瓢虫可取食烟粉虱的卵、若虫、伪蛹等各虫态,可有效地控制烟粉虱种群,具有很好的利用价值。在(26±1)℃条件下,越南斧瓢虫捕食烟粉虱的世代平均发育历期为20.33d,世代存活率为73.04%,雌成虫寿命为143.17d,平均单雌产卵量为284.33粒。越南斧瓢虫取食烟粉虱的内禀增长率(rm)为0.0457,净增殖率(R0)为103.4050,平均世代历期(T)为99.3626,周限增长率(λ)为1.0478。  相似文献   

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14.
The concept of energy serves biologists as a powerful analytical model to describe phenomena that occurs in the natural world. Due to the concept’s relevance, educational standards of different countries identify energy as a core idea for the teaching and learning of biology and other science subjects. However, previous research on students’ energy understanding has mostly focused on physics contexts. This cross-sectional study extends insight to the field by providing a systematic analysis of students’ (N = 30, grades 5, 7, 9, 11) conceptions about energy in biological contexts. In order to connect the findings to previous research, the study analyses conceptions about four energy aspects that are regarded as central for understanding the concept in different disciplinary contexts, i.e. (1) energy forms/sources, (2) transfer/transformation, (3) degradation/dissipation and (4) energy conservation. The findings identify substantial changes in students’ conceptions about energy between the different grade levels, but also highlight conceptions that students consistently employed across age groups. The results are discussed in the light of previous research on students’ progressing energy understanding and the connection of their energy understanding across different disciplinary contexts. Lastly, the article provides implications for the further development of energy teaching in biological contexts.  相似文献   

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上海虹桥机场土壤及草丛动物群落特征和鸟类关系研究   总被引:6,自引:1,他引:6  
20 0 0年 4月至 2 0 0 1年 3月 ,对上海虹桥机场草地土壤动物和草丛动物群落的组成、数量和季节性变化特征进行了初步的研究。土壤动物有节肢动物门、软体动物门、环节动物门等 12个目或类。其中蜱螨目和弹尾目为常年土壤动物群落的优势类群 ,各占年总捕量的 19.75 %和 2 3.14 % ;蚯蚓、多足纲、等足目、膜翅目、鞘翅目为常见类群 ,5类全年占总捕量的 4 8.96 %。草丛动物有 15目或类。其中鞘翅目、直翅目、半翅目、同翅目、膜翅目、双翅目以及蜘蛛目为草丛动物群落的优势类群 ,占全年总捕量的89.6 3%。草丛动物类群数和个体数总体表现为 :7月 >9月 >5月 >4月 >12月 >3月。土壤动物和草丛动物的分布与生境密切相关。所捕的 2 2类草地动物中 ,可直接被鸟类捕食的有近 2 0类 ,主要为生活于草地常见类群中 ,因此 ,草地的生境以及草地动物的分布是吸引鸟类到机场栖息和摄食的主要原因。降低草高、减少结实的植物、控制土壤动物的密度是减少机场区鸟类数量的有效方法和途径。  相似文献   

18.
利用RT-PCR技术对我国广州地区急性性戊型肝炎病毒细胞培养分离株G93-1、G93-2、G93-3和G93-4基因组聚合酶区部分核苷序列进行检测,PCR阳性产物经纯化、克隆后测定。结果G93-1、G93-3和G93-4株病毒的这段序列完全相同,且与我国新疆暴发流行的HEV87A株及HEV代表株的同源性为100%;而G93-2株与它们的差异较大,同源性只有79.9%;但是,它与1997年厦门地区急  相似文献   

19.
建立了15种中国独荇菜属植物和秘鲁原产的玛咖的性状矩阵,并采用SPSSV11.0软件建立了树谱图,以此检验《中国植物志》有关该属植物形态学分类的正确性,同时确立玛咖与该属其他植物之间的相互亲缘关系,为研究玛咖的育种、栽培提供理论依据。  相似文献   

20.
在云南2种生态条件下,对基因枪法获得的转溶菌酶基因水稻高代品系D2-1-2和受体品种中花9号的农艺性状、稻米蛋白质含量、氨基酸含量和11种矿质元素进行了对照分析。结果表明转基因品系和受体对照在生育期农艺性状上无明显的差异,但转基因水稻结实率和株高明显低于受体品种;转基因水稻糙米蛋白质含量、氨基酸含量以及9种矿质元素含量都有所增加,其中钙、铁和锌等元素增加幅度较大。认为基因枪法转基因植物可能会产生一些潜在的遗传变异,因此,建议应对转基因植物进行多年多点的环境风险评价。  相似文献   

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